Lemon trees grow in tropical and sub-tropical regions of the United States. Dwarf lemon trees are often grown in the colder states as a houseplant. The tree cannot withstand temperatures that drop below 22 degrees Fahrenheit. Fruit and flowers are typically damaged at temperatures below 28 degrees Fahrenheit. A lemon tree can easily grow 20 feet tall and 15 feet wide in the ideal outdoor setting. Numerous varieties of lemon trees exist, and they offer varying degrees of fruit production. Most varieties also have sharp thorns. Lemon trees were first grown successfully in California in 1751.
Plant lemon trees in an area that offers some wind protection. Heavy winds will defoliate a lemon tree and scar the fruit.
Plant in soil that has a pH balance of between 5.5 to 6.5. If the soil is too acidic, add lime at a rate that is necessary to achieve the ideal pH balance. Lemon trees do not require fertile soil. In Florida they thrive in soil that is virtually nothing but sand.
Plant all lemon trees a minimum of 25 feet apart for optimum growth, fruit production and spread.
Fertilize the lemon tree three times a year. Fertilize once in mid-September, again in January and again the latter part of April. Choose a fertilizer for lemon trees that offers equal parts of nitrogen and potash. Apply between 4 to 10 pounds of fertilizer per tree depending the tree size. A small tree will do fine with 4 pounds but a fully-grown, extra-large tree will need 10 pounds of fertilizer to thrive. Spread fertilizer one foot from the tree trunk and water thoroughly until all fertilizer is watered into the soil.
Purchase a nutritional spray with copper to spray on the foliage of the lemon tree. Spray after flowering. Follow the directions on the label and make sure that the nutritional spray with copper is for lemon trees. Many brands can be purchased at local garden centers.
Water the lemon tree several times a week. Do not overwater but allow the soil to become quite moist and then dry out a bit before watering again.